This application claims priority to Japanese Patent Application No. 2001-176183 filed Jun. 11, 2001, which application is hereby expressly incorporated by reference.
The present invention generally relates to a wire harness, in particular, to a wire harness which ensures that a branch line can be supported in a predetermined routing orientation.
A wire harness, which is produced by combining a plurality of wires, is wired throughout a vehicle body to form various kinds of electrical circuits.
FIG. 9 shows part of a conventional production process for a wire harness W/H-1 as shown in FIG. 10(A). These wire harness W/H-1 include two groups of wires D-1, D-2. The wires D-1, D-2 are set in jigs J upstanding from a flat plate-shaped assembly board Z. Tape T is wound on the wires at predetermined locations to bundle the wires, then necessary parts such as clips, protection parts and connectors are attached to the wires.
As shown in FIG. 10(A), the wire harness W/H-1 has a trunk line K-1 and branch lines S-1, S-2. The branch lines S-1, S-2 branch from the trunk line K-1 at branch portions to form predetermined electrical circuits. The tape T is also wound on the branch portions to prevent slack in the branch. The wire harness W/H-1 is manufactured on a flat surface of the assembly board. Accordingly, the wire harness W/H-1 is formed into a generally two-dimensional configuration. The branch lines S-1, S-2 extend generally two dimensionally relative to the trunk line K-1, as shown in FIGS. 10(B) and 10(C).
However, it is often necessary to install and route the thus constructed wire harness W/H-1 to the vehicle body in a specified orientation. For example, as shown in FIGS. 10(B) and 10(C), the trunk line K-1 must be routed so that an upper peripheral surface K-1a faces upwardly. A lower peripheral surface faces downwardly. The branch lines S-1, S-2 must be routed three-dimensionally relative to the trunk line K-1 to extend and connect to on-vehicle electronic devices (not shown). More specifically, the branch line S-1 must be routed to extend upwardly, while the branch line S-2 must be routed to extend diagonally downwardly toward the left, as shown in FIG. 11.
The above prior art construction has the following drawbacks. First, the branch lines S-1, S-2 are manufactured so that they extend generally two-dimensionally from the trunk line K-1. Thus, to route the branch lines S-1, S-2 in the proper orientations as described above (i.e., in three-dimensional orientations), the branch lines S-1, S-2 must be forcibly bent. This causes root portions of the branch lines S-1, S-2 to bulge, and take up considerably routing space. Particularly, in cases where the wire harness W/H-1 is used in small-sized vehicles, it is difficult to secure sufficient routing space. Thus, routing the wire harness W/H-1 itself is difficult.
Second, even if the branch lines S-1, S-2 are forcibly bent, it is difficult to keep them oriented properly due to the restoring forces of the bundles of wires that constitute the branch lines S-1, S-2. Thus, the branch lines S-1, S-2 might be routed off the predetermined routing paths causing interference with surrounding parts B-1, B-2. More particularly, if the branch lines S-1, S-2 interfere with edge portions of the parts B-1, B-2, the wires of the branch lines S-1, S-2 may be damaged or in the worst case, broken. To prevent any damage to the wires, it is necessary to attach a protection member such as a protection tube C to an area where the wire damage or breakage is likely to take place. This increases material and production costs.
The present invention has been developed, taking the above problems into consideration. The invention aims to ensure that a branch line of a wire harness may be supported in a predetermined routing orientation.
In a preferred form, the present invention includes a wire harness having a trunk line, a branch line and a wire tie member. The trunk line includes a bundle of wires. The branch line branches from the trunk line at a branch portion, and has at least one wire. The wire tie member has a tie strap and a buckle. A non-tying portion of the tie strap encircles and holds the bundle of wires of the trunk line adjacent the branch portion. The branch line is disposed along and is tightly secured to the non-tying portion of the tie strap. Hence, the branch line can be supported in a predetermined routing orientation relative to the trunk line.
In one aspect of the present invention, the wire tie member is mounted in such a manner that the non-tying portion of the tie strap projects in substantially the same orientation as the predetermined routing orientation of the branch line.
In a further aspect of the present invention, a securing member tightly secures the branch line to the non-tying portion of the tie strap. Preferably, the securing member is an adhesive tape.
In a further aspect of the present invention, the securing member is secured at least near a protruding end of the non-tying portion. This prevents the protruding end from moving away from the branch line. In turn, this prevents interference with surrounding parts when the branch line is routed in the predetermined routing orientation.
In another aspect of the present invention, the wire tie member has an engaging portion projecting from the buckle to engage the branch portion to a panel member. The engaging portion may be provided along an axis of the tie strap in a pre-mounting condition. Alternatively, the engaging portion may be offset from an axis of the tie strap in a pre-mounting condition. Preferably, the wire tie member is a one-piece unitary member made of resin.
In another preferred form, the present invention provides a wire harness with a trunk line, a branch line and a wire tie member. The trunk line includes a bundle of wires. The branch line branches from the trunk line at a branch portion, and has at least one wire. The tie member has a tie strap to encircle the bundle of wires of the trunk line. The tie member further has a buckle at one end of the strap. The buckle is configured to enable the other end of the tie strap to pass through the buckle and engage the tie strap intermediate the ends to secure the tie strap in place on the bundle of wires. A non-tying portion extends between the other end of the tie strap and the buckle. The non-tying portion projects in substantially the same orientation as a predetermined routing orientation of the branch line. The wire tie member is mounted adjacent the branch portion. The branch line is disposed along, and is tightly secured to the non-typing portion. Hence, the branch line is supported in the predetermined routing orientation relative to the trunk line.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.